Apparatuses for making and using bi-modal abrasive slurries for mechanical and chemical-mechanical planarization of microelectronic-device substrate assemblies

ABSTRACT

A method and apparatus for making and using slurries for planarizing microelectronic-device substrate assemblies in mechanical and/or chemical-mechanical planarization processes. In one aspect of the invention, a bi-modal slurry is fabricated by removing a first type of selected abrasive particles from a first abrasive particle solution to form a treated flow of the first solution. The treated flow of the first solution is then combined with a flow of a second solution having a plurality of second abrasive particles. The abrasive particles of the first type are accordingly removed from the first solution separately from the second solution such that the second abrasive particles in the second solution do not affect the removal of the abrasive particles of the first type from the first solution. In another aspect of the invention, a second type of selected abrasive particles are removed from the second solution prior to mixing with the first solution. Thus, by combining the treated flow of the first solution with either the treated or untreated flow of the second solution, a single flow of an abrasive slurry is produced having a first distribution of the first abrasive particles about a first mode and a second distribution of the second abrasive particles about a second mode.

TECHNICAL FIELD

[0001] The present invention relates to bi-modal slurries forplanarizing microelectronic-device substrate assemblies, and to methodsand apparatuses for making and using such slurries in mechanical and/orchemical-mechanical planarization processes.

BACKGROUND OF THE INVENTION

[0002] Mechanical and chemical-mechanical planarizing processes(collectively “CMP”) are used in the manufacturing of microelectronicdevices for forming a flat surface on semiconductor wafers, fieldemission displays and many other microelectronic-device substrateassemblies. CMP processes generally remove material from a substrateassembly to create a highly planar surface at a precise elevation in thelayers of material on the substrate assembly.

[0003]FIG. 1 schematically illustrates an existing web-formatplanarizing machine 10 for planarizing a substrate assembly 12. Theplanarizing machine 10 has a support table 14 with a top panel 16 at aworkstation where an operative portion (A) of a polishing pad 40 ispositioned. The top panel 16 is generally a rigid plate to provide aflat, solid surface to support the operative section of the polishingpad 40 during planarization.

[0004] The planarizing machine 10 also has a plurality of rollers toguide, position and hold the polishing pad 40 over the top panel 16. Therollers include a supply roller 20, first and second idler rollers 21 aand 21 b, first and second guide rollers 22 a and 22 b, and a take-uproller 23. The supply roller 20 carries an unused or preoperativeportion of the polishing pad 40, and the take-up roller 23 carries aused or post-operative portion of the polishing pad 40. Additionally,the first idler roller 21 a and the first guide roller 22 a stretch thepolishing pad 40 over the top panel 16 to hold the polishing pad 40stationary during operation. A drive motor (not shown) drives at leastone of the supply roller 20 and the take-up roller 23 to sequentiallyadvance the polishing pad 40 across the top panel 16. As such, cleanpreoperative sections of the polishing pad 40 may be quickly substitutedfor used sections to provide a consistent surface for planarizing thesubstrate assembly 12.

[0005] The web-format planarizing machine 10 also has a carrier assembly30 that controls and protects the substrate assembly 12 duringplanarization. The carrier assembly 30 generally has a carrier head 31with a plurality of vacuum holes 32 to pick up and release the substrateassembly 12 at appropriate stages of the planarizing cycle. A pluralityof nozzles 41 attached to the carrier head 31 dispense a planarizingsolution 42 onto a planarizing surface 43 of the polishing pad 40. Thecarrier assembly 30 also generally has a support gantry 34 carrying adrive assembly 35 that translates along the gantry 34. The driveassembly 35 generally has actuator 36, a drive shaft 37 coupled to theactuator 36, and an arm 38 projecting from the drive shaft 37. The arm38 carries the carrier head 31 via another shaft 39 such that the driveassembly 35 orbits the carrier head 31 about an axis B-B offset from acenter point C-C of the substrate assembly 12.

[0006] The polishing pad 40 and the planarizing solution 42 define aplanarizing medium that mechanically and/or chemically-mechanicallyremoves material from the surface of the substrate assembly 12. Theweb-format planarizing machine 10 typically uses a fixed-abrasivepolishing pad having a plurality of abrasive particles fixedly bonded toa suspension material. The planarizing solutions 42 used withfixed-abrasive pads are generally “clean solutions” without abrasiveparticles because the abrasive particles in conventional abrasive CMPslurries may ruin the abrasive surface of fixed-abrasive pads. In otherapplications, the polishing pad 40 may be a nonabrasive pad composed ofa polymeric material (e.g., polyurethane), a resin, or other suitablematerials without abrasive particles. The planarizing solutions 42 usedwith nonabrasive polishing pads are typically “abrasive” CMP slurrieswith abrasive particles.

[0007] To planarize the substrate assembly 12 with the planarizingmachine 10, the carrier assembly 30 presses the substrate assembly 12against the planarizing surface 43 of the polishing pad 40 in thepresence of the planarizing solution 42. The drive assembly 35 thenorbits the carrier head 31 about the offset axis B-B to translate thesubstrate assembly 12 across the planarizing surface 43. As a result,the abrasive particles and/or the chemicals in the planarizing mediumremove material from the surface of the substrate assembly 12.

[0008] CMP processes should consistently and accurately produce auniformly planar surface on the substrate assembly 12 to enable precisefabrication of circuits and photo-patterns. For example, during thefabrication of transistors, contacts, interconnects and othercomponents, many substrate assemblies develop large “step heights” thatcreate a highly topographic surface across the substrate assembly 12. Toenable the fabrication of integrated circuits with high densities ofcomponents, it is necessary to produce a highly planar substrate surfaceat several stages of processing the substrate assembly 12 becausenon-planar substrate surfaces significantly increase the difficulty offorming submicron features. For example, it is difficult to accuratelyfocus photo-patterns to within tolerances of 0.1 μm on nonplanarsubstrate surfaces because submicron photolithographic equipmentgenerally has a very limited depth of field. Thus, CMP processes areoften used to transform a topographical substrate surface into a highlyuniform, planar substrate surface.

[0009] In the competitive semiconductor industry, it is also highlydesirable to have a high yield of operable devices after CMP processingby quickly producing a uniformly planar surface at a desired endpoint ona substrate assembly. For example, when a conductive layer on thesubstrate assembly 12 is under-planarized in the formation of contactsor interconnects, many of these components may not be electricallyisolated from one another because undesirable portions of the conductivelayer may remain on the substrate assembly 12. Additionally, when asubstrate assembly 12 is over-planarized, components below the desiredendpoint may be damaged or completely destroyed. Thus, to provide a highyield of operable microelectronic devices, CMP processing should quicklyremove material until the desired endpoint is reached.

[0010] To accurately create highly planar substrate surfaces at thedesired endpoint, the particle size distribution of planarizing slurriesshould be consistent from one planarizing cycle to another. One problemwith CMP processing, however, is that the abrasive particles may beunstable in the slurry. For example, because many types of abrasiveparticles have a large affinity for one another, individual particles ina liquid solution may agglomerate into larger abrasive elements. Theformation of such abrasive elements affects the consistency of theslurry because the extent that the particles agglomerate varies from onebatch of slurry to another, or even within a single batch of slurry asit is delivered to the planarizing machine. Additionally, large abrasiveelements may scratch the substrate assemblies and produce defects, orthey may settle out of the solution. Thus, the agglomeration of abrasiveparticles is a serious problem for processing substrate assemblies withCMP processing.

[0011] One particularly promising CMP slurry being developed by MicronTechnology, Inc. is a liquid solution having a plurality of first andsecond abrasive particles. The first and second abrasive particles aretypically composed of the same material, such as ceria or silica treatedceria abrasive particles. The difference between the first and secondabrasive particles is the size of the particles. This slurry accordinglyhas a “bi-modal” distribution of abrasive particles in which the firstabrasive particles have particles sizes in a first size distributionabout a first mode and the second abrasive particles have particle sizesin a second size distribution about a second mode. In contrast to“singlet” slurries that have only one mode and a signal sizedistribution of abrasive particles about that mode, bi-modal slurriesare expected to exhibit unusually good polishing rates and planarity onboth topographical and planar substrate surfaces.

[0012] Although bi-modal slurries can produce good results, they mayfail to achieve consistent results because the abrasive particles arehighly unstable in the solution. The bi-modal slurries mixed by MicronTechnology Inc. from components supplied by Rodel Corporation may evenchange from one planarizing cycle to the next, which greatly increasesthe difficulty in accurately planarizing substrate assemblies. Toresolve the instability of these slurries, a point-of-use filtering maybe performed at the planarizing machine of a single flow of a bi-modalslurry having both the first and second planarizing particles. Filteringthe bi-modal slurry, however, may alter the bi-modal distribution ofabrasive particles to the extent that the bi-modal slurry loses at leastsome of the advantages of using two different particle sizes. Therefore,there is a need for improved bi-modal slurry techniques in CMPprocessing to achieve the potential advantages of such slurries.

SUMMARY OF THE INVENTION

[0013] The present invention is directed toward methods and apparatusesfor making and using slurries for planarizing microelectronic-devicesubstrate assemblies in-mechanical and/or chemical-mechanicalplanarization processes. In one aspect of the invention, a bi-modalslurry is fabricated by removing a first type of selected abrasiveparticles from a first abrasive particle solution to form a treated flowof the first solution. The treated flow of the first solution is thencombined with a flow of a second solution having a plurality of secondabrasive particles. A single flow of an abrasive slurry thus has a firstdistribution of the first abrasive particles and a second distributionof the second abrasive particles.

[0014] In another aspect of the invention, a bi-modal abrasive slurry ismanufactured by also separating a second type of selected abrasiveparticles from the second solution prior to combining the first solutionwith the second solution. Thus, the first and second solutions can betreated independently to avoid affecting the treatment of one solutionby treating the other solution.

[0015] In still another aspect of the invention, a planarizing apparatusfor planarizing a substrate assembly in accordance with the inventionincludes a slurry manufacturing assembly, and a dispenser coupled to theslurry manufacturing assembly. The slurry manufacturing assembly caninclude a first feed line for containing the first flow of the firstsolution having the plurality of the first abrasive particles, a secondfeed line for containing the second flow of the second solution havingthe plurality of second abrasive particles, a first filter coupled tothe first feed line to filter the plurality of the first abrasiveparticles separately from the second flow of the second solution, and acombined feed line operatively coupled to the first filter and thesecond feed line for containing a combined flow of the first and secondsolutions after filtering the first solution.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a schematic cross-sectional view of a planarizingmachine in accordance with the prior art.

[0017]FIG. 2 is a schematic side view of a planarizing system includinga planarizing machine and a slurry manufacturing assembly in accordancewith one embodiment of the invention.

[0018]FIG. 3 is a block diagram illustrating first and second slurrysolutions being processed according to a method for making a planarizingsolution in accordance with an embodiment of the invention.

[0019]FIG. 4 is a bar graph illustrating a slurry made using a slurrymanufacturing assembly and method in accordance with one embodiment ofthe invention having a bi-modal particle size distribution including afirst size distribution of first abrasive particles about a first modeand a second size distribution of smaller second abrasive particlesabout a second mode.

[0020]FIG. 5 is a schematic side view of a planarizing system includinga planarizing machine and a slurry manufacturing assembly in accordancewith another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention is directed to methods and apparatuses formaking and using slurries for planarizing microelectronic-devicesubstrate assemblies in mechanical and/or chemical-mechanicalplanarization processes. Many specific details of certain embodiments ofthe invention are set forth in FIGS. 2-5 and the following descriptionto provide a thorough understanding of such embodiments. One skilled inthe art, however, will understand that the present invention may haveadditional embodiments, or that certain embodiments of the invention maybe practiced without several of the details described in the followingdescription.

[0022]FIG. 2 is a schematic side view illustrating a planarizing system100 having a planarizing machine 110 and a slurry manufacturing assembly200 in accordance with one embodiment of the invention. The planarizingmachine 110 shown in FIG. 2 is similar to the web-format planarizingmachine 10 described above with reference to FIG. 1, and thus likereference numbers refer to like parts. The planarizing machine 110 canalso be a rotary planarizing machine having a rotating platen and acircular polishing pad, as set forth in U.S. Pat. Nos. 5,645,682 and5,792,709, which are both herein incorporated by reference. Suitableweb-format planarizing machines without the slurry manufacturingassembly 200 are manufactured by Obsidian Corporation. Suitable rotaryplanarizing machines without the slurry manufacturing assembly 200 aremanufactured by Westech Corporation and Strasbaugh Corporation.

[0023] The slurry manufacturing assembly 200 generally includes a firstsupply container 210 containing a first solution 212 and a second supplycontainer 220 containing a second solution 222. In this particularembodiment, the slurry manufacturing assembly 200 also includes a firstparticle removal unit 230 coupled to the first container 210, a secondparticle removal unit 235 coupled to the second container 220, and amixing unit 240 coupled to the first and second particle removal units230 and 235. As explained below, the first and second particle removalunits 230 and 235 are preferably first and second filtration units thatseparately filter selected abrasive particles from the first and secondsolutions 212 and 222. The filtered first and second solutions 212 and222 are then combined in the mixing unit 240 to form an abrasive slurry242 for planarizing the substrate assembly 12 on the planarizing machine110.

[0024] The first solution 212 is a first slurry component of theabrasive slurry 242. The first solution 212 preferably includes water,chemical additives (e.g., dispersants, surfactants, oxidants and otheradditives), and a plurality of first abrasive particles 216. The firstabrasive particles 216 can be aluminum oxide particles, ceria particles,silicon dioxide particles, titanium oxide particles, tantalum oxideparticles, ceria treated silica particles, or other suitable abrasiveparticles for removing material from microelectronic device substrateassemblies. The first abrasive particles 216 are preferably the largerparticles of a bi-modal abrasive slurry having particle sizes fromapproximately 0.070-1.0 μm, and more preferably from approximately0.070-0.40 μm. When the first solution 212 is in the first container 210prior to being mixed with the second solution 222, a significantpercentage of the first abrasive particles 216 in the first solution 212may agglomerate to form first particle agglomerations 218. Each firstparticle agglomeration 218 may accordingly include two or moreindividual abrasive particles 216. The individual abrasive particles 216of the first particle agglomerations 218 are generally bonded togetherelectronically, covalently, or by van der walls interaction.

[0025] The second solution 222 is accordingly a second component of themixed slurry 242. The second solution 222 generally includes a liquid224, the same additives that are in the first solution 212, and aplurality of second abrasive particles 226. The second abrasiveparticles 226 can also be composed of the same material as the firstabrasive particles 216 in the first solution 212, such as aluminum oxideparticles, ceria particles, silicon dioxide particles, titanium oxideparticles, tantalum oxide particles, ceria treated silica particles, orother suitable abrasive particles for removing material frommicroelectronic device substrate assemblies. The second abrasiveparticles 226 are preferably the smaller particles of a bi-modalabrasive slurry having particle sizes from approximately 0.005-0.20 μm,and more preferably from approximately 0.010-0.050 μm. As with the firstsolution 212, many of the abrasive particles 226 in the second solution222 may agglomerate into second particle agglomerations 228.

[0026] The first particle removal unit 230 of this embodiment is coupledto a first feed line 219 (indicated by reference numbers 219 a and 219b) between the first container 210 and the mixing unit 240. The firstparticle removal unit 230 removes a first type of selected abrasiveparticles from the first solution 212. The first particle removal unit230, for example, can have a filter 232 that removes large individualabrasive particles 216 and first particle agglomerations 218 havingsizes greater than a first maximum particle size for the first abrasiveparticles. For example, to create a first particle size distributionfrom approximately 0.070-1.0 μm, the first particle removal unit 230removes first abrasive particles 216 and particle agglomerations 218having sizes greater than 1.0 μm. Similarly, to create a first particlesize distribution from approximately 0.070-0.40 μm, the first particleremoval unit 230 removes first abrasive particles 216 and particleagglomerations 218 having sizes greater than 0.40 μm. Suitable filtersfor removing the first type of selected abrasive particles from thefirst solution 212 are manufactured by Millipore Corporation.

[0027] The second particle removal unit 235 of this embodiment iscoupled to a feed line 229 (indicated by reference numbers 229 a and 229b) between the second container 220 and the mixing unit 240. The secondparticle removal unit 235 removes a second type of abrasive particlesfrom the second solution 222. The second particle removal unit 235 canalso have a filter 237 that removes large second abrasive particles 226and second particle agglomerations 228 having sizes greater than asecond maximum particle size. For example, to create a second particlesize distribution from approximately 0.010-0.20 μm, the second particleremoval unit 235 removes second abrasive particles 226 and particleagglomerations 228 having sizes greater than 0.20 μm. Similarly, tocreate a second particle size distribution from approximately0.010-0.050 μm, the second particle removal unit 235 removes secondabrasive particles 226 and particle agglomerations 228 having sizesgreater than 0.050 μm. Suitable filters for removing the second type ofselected abrasive particles from the second abrasive particles 226 arealso manufactured by Millipore Corporation.

[0028]FIG. 3 is a schematic view illustrating the operation of theembodiment of the slurry manufacturing assembly 200 shown in FIG. 2.Referring to FIGS. 2 and 3 together, an untreated flow of the firstsolution 212 initially flows to the first particle removal unit 230through a first segment of the first feed line 219 a, and an untreatedflow of the second solution 222 initially flows to the second particleremoval unit 235 through a first segment of the second feed line 229 a.The first particle removal unit 230 passes the untreated flow of thefirst solution 212 through the filter 232 to remove large individualfirst abrasive particles 216 a and large first particle agglomerations218 from the first solution 212. A treated portion of the first solution212 then passes from the first particle removal unit 230 through asecond segment of the first feed line 219 b and into the mixing unit240. The second particle removal unit 235 separately passes theuntreated flow of the second solution 222 through the filter 237 toremove the large individual abrasive particles 226 and second particleagglomerations 228 from the untreated second solution 222 to create atreated flow of the second solution 222. The second particle removalunit 235 then passes the treated flow of the second solution 222 througha second segment of the second feed line 229 b and into the mixing unit240.

[0029] The mixing unit 240 then mixes the treated first and secondsolutions 212 and 222 together by using an agitator 241, turbulencewithin a conduit, and/or other suitable devices for adequately mixingthe first and second solutions 212 and 222. The combination of the firstand second solutions 212 and 222 forms an abrasive slurry 242 with afirst particle size distribution of larger first abrasive particles 216about a first mode and a second particle size distribution of smallersecond abrasive particles 226 about a second mode.

[0030]FIG. 4 is a bar graph illustrating a bi-modal particle sizedistribution of the planarizing slurry 242 having a first particle sizedistribution 280 from approximately 0.20-1.0 μm of the larger firstabrasive particles 216 (FIG. 2) and a second particle size distribution290 from approximately 0.020-0.20 μm of the smaller second abrasiveparticles 226 (FIG. 2). The first particle size distribution 280 has afirst mode 282 identifying that a significant percentage of the firstabrasive particles 216 have particle sizes of approximately 0.3-0.4 μm.The second particle size distribution 290 has a second mode 292identifying that a significant percentage of the second abrasiveparticles 226 have particle sizes of approximately 0.07-014 μm. Inanother embodiment (not shown), the first particle size distribution isfrom approximately 0.070-0.400 μm with a first mode at approximately0.250-0.300 μm, and the second particle size distribution is fromapproximately 0.010-0.050 μm with a second mode at approximately0.020-0.030 μm.

[0031] The embodiment of the slurry manufacturing assembly 200 and themethod of manufacturing the slurry 242 described above with reference toFIGS. 2 and 3 are expected to produce bi-modal planarizing slurries withconsistent first and second particle size distributions. One aspect ofthe embodiment of FIGS. 2-4 is the discovery that conventional filteringprocesses for a bi-modal slurry produce inconsistent particle sizedistributions because the filters remove a disproportionate percentageof the larger first abrasive particles after operating for a period oftime. This phenomenon may occur because a common filter sized to removethe upper end of the larger particles is generally too large to alsoremove agglomerations of the smaller particles. Moreover, as the filterbecomes loaded with abrasive particles, the removal rate of largerabrasive particles increases without necessarily increasing the removalrate of the smaller second abrasive particles. The slurry manufacturingsystem 200 and the methods for making the slurry 242 reduce variationsin the first and second particle size distributions because the firstand second solutions 212 and 222 are filtered separately to provide moreconsistent filtering of the individual solutions. The slurrymanufacturing system 200 is accordingly expected to have less loading ofthe filters in a manner that removes a disproportionate percentage ofthe first abrasive particles 216 from the planarizing solution 242.Thus, the manufacturing system 200 and the methods for manufacturing theplanarizing slurry 242 are expected to provide more consistent first andsecond particle size distributions in a bi-modal slurry.

[0032] The bi-modal slurry 242 manufactured in accordance with themethod described above with reference to FIGS. 2 and 3 is also expectedto produce good planarizing results. Small abrasive particles areexpected to planarize highly topographic surfaces much faster than largeabrasive particles. Once the surface of the substrate assembly becomesplanar, however, slurries with small particles may have a much slowerremoval rate than slurries with large particles. The bi-modalplanarizing solution 242 manufactured in accordance with the embodimentof FIGS. 2-4 includes the small second abrasive particles 226 to provideselective removal of high areas on the substrate surface at an initialstage of a planarizing cycle while the substrate surface hastopographical variations. The bi-modal slurry 242 also includes thelarger first abrasive particles 216 for maintaining a high removal rateonce the substrate surface becomes planar. The planarizing solution 242accordingly provides selective removal of the topographical features toform a planar surface on the substrate assembly, and then maintains ahigh removal rate of material from the blanket surface to expedientlyplanarize the substrate assemblies.

[0033]FIG. 5 is a schematic view illustrating a planarizing system 100 ahaving the planarizing machine 110 and a slurry manufacturing assembly200 a in accordance with another embodiment of the invention. In thisembodiment, the slurry manufacturing assembly 200 a has the first supplycontainer 210 containing the first solution 212, the second supplycontainer 220 containing the second solution 222, and only the firstparticle removal unit 230 coupled to the first container 210 and themixing unit 240. The slurry manufacturing assembly 200 a accordinglyonly treats the flow of the first solution 212 to filter or otherwiseremove the first type of selected abrasive particles from the firstabrasive particles 216. The planarizing system 100 a is otherwiseexpected to operate in a manner similar to the planarizing system 100described above.

[0034] Referring to FIG. 2 or FIG. 5, the substrate 12 is planarized byfabricating the mixed slurry 242 and then depositing the mixed slurry242 onto the polishing pad 40 via the nozzles 41 on the carrier head 31.As the mixed slurry 242 covers the polishing pad 40, the carrierassembly 30 presses the substrate 12 against the planarizing surface 43of the pad 40 and translates the substrate 12 across the planarizingsurface 43. Because the slurry manufacturing assemblies 200 and 200 aproduce slurries with consistent first and second particle sizedistributions, the planarizing systems 100 and 100 a are expected toconsistently produce highly planar and substantially defect freesurfaces on the finished substrate assemblies 12.

[0035] From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1-69. (Cancelled)
 70. A planarizing apparatus for planarization of microelectronic-device substrate assemblies, comprising: a table for carrying a polishing pad; a carrier assembly having a carrier head configured to hold a substrate assembly, the carrier head being movable to press the substrate assembly against the polishing pad, and at least one of the carrier head or the table being translatable with respect to the other to translate the substrate assembly across the polishing pad; a slurry manufacturing assembly including a first feed line for containing a flow of a first solution having a plurality of first abrasive particles, a second feed line for containing a separate flow of a second solution having a plurality of second abrasive particles of a different type than the first abrasive particles, a first removal unit coupled to the first feed line to selectively remove a first type of selected abrasive particles from the first abrasive particles, and a combination feed line operatively coupled to the first removal unit and the second feed line for containing a combined flow of the first and second solutions after removing the first type of selected abrasive particles from the first solution; and a slurry dispenser coupled to the combination line to dispense the abrasive slurry, the dispenser being positionable over the table to dispense the slurry from the combination line onto the planarizing pad.
 71. The planarizing apparatus of claim 70 wherein the first removal unit comprises a first filtration unit.
 72. The planarizing apparatus of claim 71 wherein the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 1.0 μm.
 73. The planarizing apparatus of claim 70, further comprising a second removal unit coupled to the second feed line to selectively remove a second type of selected abrasive particles from the second abrasive particles, and wherein the combination feed line is coupled to the second removal unit to contain a combined flow of the first and second solutions after removing the first and second types of selected abrasive particles from the first and second solutions.
 74. The planarizing apparatus of claim 73 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.3 μm; and the second filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.05 μm.
 75. The planarizing apparatus of claim 70 wherein the first removal unit comprises a first filtration unit that removes abrasive particles having a particle size greater than approximately 0.8 μm.
 76. The planarizing apparatus of claim 70 wherein the first removal unit comprises a first filtration unit that removes abrasive particles having a particle size greater than approximately 0.3 μm.
 77. The planarizing apparatus of claim 73 wherein the second removal unit comprises a first filtration unit that removes abrasive particles having a particle size greater than approximately 0.15 μm.
 78. The planarizing apparatus of claim 73 wherein the second removal unit comprises a first filtration unit that removes abrasive particles having a particle size greater than approximately 0.05 μm.
 79. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 1.0 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 80. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 1.0 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 81. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.8 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 82. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.8 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 83. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.3 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 84. The planarizing apparatus of claim 74 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.3 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 85. The planarizing apparatus of claim 70 further comprising a mixing unit configured to mix the combined flow of the first and second solutions.
 86. The planarizing apparatus of claim 70 further comprising a conduit through which the combined flow of the first and second solutions is passed to provide a turbulent zone for mixing the combined flow.
 87. The planarizing apparatus of claim 70 further comprising a volume control unit configured to mix 1-99% by volume of the first filtered solution with 1-99% by volume of the second solution.
 88. The planarizing apparatus of claim 87 wherein the volume control unit is configured to alter a mix ratio of the first filtered solution and the second solution during a single polishing cycle.
 89. The planarizing apparatus of claim 88 wherein the volume control unit is configured to change from a first mix ratio of the first filtered solution and the second solution to a second mix ratio of the first filtered solution and the second solution.
 90. A planarizing apparatus for planarization of microelectronic-device substrate assemblies, comprising: a table for carrying a polishing pad; a carrier assembly having a carrier head configured to hold a substrate assembly, the carrier head being movable to press the substrate assembly against the polishing pad, and at least one of the carrier head or the table being translatable with respect to the other to translate the substrate assembly across the polishing pad; a slurry manufacturing assembly including a first feed line for containing a flow of a first solution having a plurality of first abrasive particles, a second feed line for containing a separate flow of a second solution having a plurality of second abrasive particles of a different type than the first abrasive particles, a first filtration unit coupled to the first feed line to selectively filter a first type of selected abrasive particles from the first abrasive particles, a combination feed line operatively coupled to the first removal unit and the second feed line for containing a combined flow of the first and second solutions after removing the first type of selected abrasive particles from the first solution; at least one of a mixer configured to mix the combined flow and a conduit through which the combined flow is passed to form a turbulent zone; and a slurry dispenser coupled to the combination line to dispense the abrasive slurry, the dispenser being positionable over the table to dispense the slurry from the combination line onto the planarizing pad.
 91. The system of claim 90, further comprising a second filtration unit coupled to the second feed line to selectively remove a second type of selected abrasive particles from the second abrasive particles, and wherein the combination feed line is coupled to the second filtration unit to contain a combined flow of the first and second solutions after removing the first and second types of selected abrasive particles from the first and second solutions.
 92. The planarizing apparatus of claim 91 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.3 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 93. The planarizing apparatus of claim 92 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 1.0 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 94. The planarizing apparatus of claim 92 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 1.0 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 95. The planarizing apparatus of claim 92 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.8 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.05 μm.
 96. The planarizing apparatus of claim 92 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.8 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 97. The planarizing apparatus of claim 92 wherein: the first filtration unit comprises a filter that removes abrasive particles having a particle size greater than approximately 0.3 μm; and the second filtration unit comprises a filter that removes abrasive particles having particle size greater than approximately 0.15 μm.
 98. The planarizing apparatus of claim 90 further comprising a volume control unit configured to mix 1-99% by volume of the first filtered solution with 1-99% by volume of the second solution.
 99. The planarizing apparatus of claim 98 wherein the volume control unit is configured to alter a mix ratio of the first filtered solution and the second solution during a single polishing cycle.
 100. The planarizing apparatus of claim 99 wherein the volume control unit is configured to change from a first mix ratio of the first filtered solution and the second solution to a second mix ratio of the first filtered solution and the second solution. 